was wondering where i could find the #'s to verify the cubes of the motor in my trans am,was originally a 305 tpi but was replaced.trying to find out if another 305 went in or was upgraded to a 350.pulls to hard for a 305 so need to check so i can order heads and cam.

 

http://www.mortec.com/location.htm

 

these are the only numbers i could get to without taken everything off the front of the motor.14101081,dealer said they couldn't do nothing with those because it had to be numbers and letters.also found next to it c098 or 0098 or 8600(that one if i was looking at it upside down.any more help on this would be appreciated because i can't really order heads and cam until i know for sure.lloking for low 8's in a 1/8th so don't know if i need a 350.

 

Those are 305 heads.

Doesn't "prove" it's a 305, as they'll fit a 350; but I'd say it ups the odds quite a bit, that that's what it is.

We've probably all heard the "runs too good to be a 305" sucker line before at least once; a few here on this board, I know, unfortunately have bit on that one and bought cars that were "said" to be a 350 for that reason, and then when they checked the numbers, guess what?? . That's real common used car salesman BS. Best to not go around saying that.



Look on the top of the bell housing flange, right behind the driver's side head. The number there is the block casting number. It will tell you for ASBOLUTELY CERTAIN what the engine is. Most later blocks will also have "5.0" or "5.7" there as well.

 

Well, if the car "pulls too hard to be a 305" there is also the possibility that the 305 in it was built well to make power. Also, the 305 heads could very well be on a 350 block, but not many people do it unless it is at least the H.O. heads. I have H.O. 305 heads on my 350, but it was more because I found out they were H.O. after getting screwed on the whole deal. Was told it was a 350, VIN confirmed it, but when I pulled the knocking motor, found a 305 block with a spun main :-( Needless to say, I replaced the block and went to the 350, but decided to keep the decent flowing heads.

Anyway, I would try and get the number off the back of the block using a mirror and some light or something if you have to to be sure what you have.

 

might just be ditching this engine 305 or not for a built 350 with 500+hp.looking to pick it up for around 2500,all i need for it is a 750 double pumper,and some headers.my hei with msd should be enough to keep it sparking.after that i have to find a rearend that will stand up to it.was hoping to get a true pontiac full posi out of something like a older trans am.i knew that 500hp 700r4 would come in handy.

 

I wouldn't go that far. LG4, HO (L69), and TPI heads are basically the same with regard to performance potential.
500+ HP isn't easy to handle. No way no how will $2500 be enough for that. I always say plan on spending as much handling the power as you do making it.

Forget a rear out of an older trans am. Won't fit without redoing all of the mounting, by the time you have it ready to go you could have purchased a 9-inch or 12-bolt from Strange or Moser (right there you're looking at almost $2500).

 

we'll have to wait and see. the motor is in a 80 camaro now and i'll be looking at it and riding in the car sunday after daytona.if iwas going to find a rearend that could stand up to a few runs down a 1/8th and still last enough to go down the road.not a bult rear,what should i look for,i heard some of the earlier 80's 3rd gens had full posi with i think 3.73's but i'm not sure any info on that would be great.i know i'd probably have to feather any non built rear off the line then get on it,so which would be the easiest and cheapest way around this.just looking for 8's in the 1/8th so a easy start then get on it shouldn't be that hard to obtain right?